One of the most important challenges in the 21st century is energy. This involves the substantial transformation towards a clean energy system that meets our future needs without substantial damage to nature.1, 2 Hydrogen (H2) is expected to play a crucial role as a secondary fuel and energy carrier in such a system.3, 4 H2 has a high gravimetric energy density of 33.3 kW·h/kg and it can be converted into energy in an internal combustion engine or fuel cells with the production of water (H2O) as the only “byproduct”.5 However, it is believed that the hydrogen economy will not occur until significant technological advances in H2 production, storage and delivery systems are made.6 Among these issues, H2 storage has represented a great challenge. Conventional H2 storage in high-pressure compressed gas cylinders or cryogenic liquid tanks is straight forward, but it suffers from high energy input and low volumetric energy capacity.7 Alternative approaches through physical adsorption of H2 in high-surface-area materials, such as metal-organic frameworks, zeolites, nanostructured carbon materials, etc., experience the limitation of temperature and pressure ranges.8-10 While chemical hydride systems have high gravimetric H2 capacities up to 20 wt %, the low reversibility prohibits their widespread applications.11-13 In this regard, formic acid (FA) becomes an attractive choice. Although FA contains only 4.35 wt % of H2, because of its high density of 1.22 g/cm3, its volumetric capacity reaches 53.0 g H2/L. This is equivalent to an energy density of 1.77 kW·h/L, suitable for automotive and mobile applications. A carbon neutral system for H2 storage can be created when efficient hydrogenation of carbon dioxide (CO2) to FA/formates and selective dehydrogenation of FA are developed.14-17 
The decomposition of FA to H2 and CO2 is thermodynamically favored, but the energy barrier is high and the selectivity is low (for the formation of H2O and CO) in the absence of a suitable catalyst. After the potential of utilizing CO2 as a H2 storage material was recognized,18, 19 a number of homogeneous and heterogeneous catalyst systems have been developed recently for the generation of H2 from FA.20-43 Reactions give significantly enhanced turnover frequencies (TOFs) and turnover numbers (TONs) by using FA/NEt3 azeotrope or FA/formate mixtures at the cost of decreasing the overall volumetric H2 capacity. Only a few molecular catalysts show good activities in the absence of base additives.25, 32, 43 
Therefore, a need exists for the development of novel catalyst systems that overcome one or more of the current disadvantages noted above.